Scientific evidence suggests that differences in diet and lifestyle may account in large part for
the variability of prostate cancer rates in different countries.1

Good nutrition may reduce the incidence of prostate cancer and help reduce the risk of prostate cancer progression. There are many studies currently being conducted to help further understand how diet and prostate cancer are related. We do know, however, that improved nutrition reduces risk of heart disease, diabetes, and obesity, and usually improves overall quality of life. It is estimated that one-third of cancer deaths in the U.S. can be attributed to diet in adulthood, including diet's effect on obesity.
2 Additionally, a healthy diet helps to increase energy levels, facilitate recovery, and enhance the immune system.

Contain vitamins, minerals, and fiber as well as various cancer-fighting phytochemicals (examples: carotenoids, lycopene, indoles, flavonols).

Vibrant, intense color is one indicator of phytochemical content.

There is extensive and consistent evidence that high fruit and vegetable intakes are associated with
decreased risks of many cancers,3-13 and while results for prostate cancer risk are not yet conclusive,
they are promising.14-17

Men who consumed at least 28 servings of vegetables per week had a reduced risk of prostate
cancer compared with those who ate fewer than 14 servings per week.15

There is some evidence that vegetables, particularly cruciferous vegetables, such as broccoli, cauliflower,
cabbage, kale, Brussels sprouts, and bok choy have been associated with a reduced risk of
prostate cancer.15-1618-20

Men who ate three or more servings of cruciferous vegetables per week had a 41% decreased
risk of prostate cancer compared with men who ate less than one serving per week.15

The benefit of fruits and vegetables in regards to cancer protection may be related to high amounts
of carotenoids in certain fruits and vegetables, according to some key population studies.16-1821-28

Additionally, organic fruits and vegetables have fewer pesticides, lower levels of total pesticides,
and less overall pesticide toxicity than fruits and vegetables grown with chemicals. Although more
research is needed, recent evidence indicates a significant increase in antioxidants in organic and
sustainably grown foods versus conventionally grown foods.29-31

Consume at least five, preferably eight to ten, servings of fruits and vegetables daily for their cancer
protective effects.32

The increased cancer risk observed in developed countries may be, in part, due to the fact that a
high fat diet stimulates increased testosterone levels, which is known to be associated with prostate
cancer growth.42-43

A comprehensive review reported that 20 of 30 studies found positive, although not all statistically
significant, associations between dietary fat intake and prostate cancer risk.44

While a positive association between prostate cancer and fat intake was not observed in all studies,45 some prospective studies did report significant findings. 46-49

Most researchers agree to aim for 20% of your total calories from fat, with less than 10% of total calories from saturated fat.41

The type of fat is significant and may, in fact, be of greater importance than total fat.

Saturated Fats

Several studies indicate a positive association between saturated fat intake from meat and dairy
products (animal sources) and prostate cancer.2150-53
Eating red meat464954-55 and
dairy products 214654-55 also appear to be related to an increased risk of metastatic prostate
cancer.

Reduce or eliminate consumption of red meat, milk, and other dairy products.

Limit use of butter, mayonnaise, baked goods, and regular salad dressings due to high saturated
fat and total fat content. Consider rice vinegar, balsamic vinegar, lemon juice, or salsa as
alternative salad dressings.

Limit cheese consumption. Cheese is typically between 60-80% fat, much of which is
saturated fat.

Trans Fatty Acids

Trans fatty acids, or hydrogenated oils, are known to be atherogenic, increasing one's risk of heart
disease.56-59

Preliminary research indicates these fats may also be associated with increased cancer risk.
1360-61

A recent prostate cancer trial reported a 30% increased cancer risk in men who used margarine
once or more daily.14

Limit use of hydrogenated fats, such as margarine, fried foods, and processed foods including
breads, crackers, cereals, and cookies that are high in harmful trans fatty acids.

When you read that a product contains hydrogenated or partially-hydrogenated oils, consider
putting it back on the shelf. (Be sure to bring your reading glasses when shopping.)

Trans fatty acid labeling should be in effect in the year 2006, when the amount of trans fatty
acids in a product will be clearly identified.

Omega-6 Fatty Acids

Omega-6 fatty acids (linoleic acid, which can be converted to arachidonic acid) may stimulate
growth of prostate cancer cells.62-65
Other studies, however, have observed no association.4966-68

Substitute olive oil or canola oil for your current cooking oil, but remember to use only in moderation.
These oils are rich in monounsaturated fats, which don't appear to increase cancer risk.
14456369

Minimize consumption (no more than ¼ cup with meal/snack) of nuts due to high fat content. This
includes peanuts, macadamia nuts, and pistachios.

Nuts are highly concentrated in monounsaturated fatty acids, which are neutral in terms of
stimulating cancer growth and may be beneficial for heart disease. They are, however,
high in fat.

Omega-3 Fatty Acids

Omega-3 fatty acids may reduce risk for prostate cancer as well as reduce the risk of cancer progression.
146370-72

Men who consumed fish 3 or more times per week also had a 44% lower risk of prostate cancer,
especially for metastatic prostate cancer where the effect was even greater.71

Researchers in New Zealand reported that men with high levels of eicosapentaenoic acid (EPA) and
docosahexaenoic acid (DHA), the omega-3 fats found in fish, had a 40% lower risk of prostate cancer
than those with low blood levels.70

A 30-year follow-up study found that men who ate no fish had a 2 to 3 times higher frequency of
prostate cancer than those who ate moderate or high amounts of fish.72

It may be wise to consume fish at least twice weekly to obtain an adequate amount of omega-3
fatty acids.
Alternatively, incorporating one of the following foods on a regular basis will help to achieve sufficient
omega-3 fatty acids:
1-2 Tbsp ground flaxseed
1 oz walnuts
½ - 1 cup cooked soybeans

Fish and plant-based foods, however, contain different types of omega-3 fatty acids.

Fish contains EPA and DHA, two specific fatty acids that have shown promising results in protecting
against cancer.

The plant-based omega-3 fatty acid sources, such as flaxseed and others listed above, contain
alpha-linolenic acid (ALA). In an ideal environment, ALA is converted to EPA and DHA, however,
this process is inefficient.75-76 On the positive side, the conversion process is enhanced by
following a diet that is low in saturated fats and low in omega-6 fatty acids.77

Although not all studies agree,6678 some research indicates a positive association between
ALA and prostate cancer.4955626879
It should be noted, however, that the primary
source of ALA in these studies was red meat, milk, butter, mayonnaise, and margarine.
495579

Substantial evidence indicates that a high caloric intake increases one's risk of various cancers,
including prostate cancer.
17527889-91

A case-control study reported a 115% increased risk in local prostate cancer and a 96% increased
risk in regional/distant prostate cancer for those consuming higher calorie diets (2439 or more calories/
day) compared with individuals consuming a lower calorie diet (less than 1322 calories/day).90

In a separate study, researchers reported a nearly four-fold increase in prostate cancer risk in men
who consumed the most calories (more than 2624 calories/day) compared with men who consumed
the least calories (1064 calories/day).91
An earlier study found that caloric intake was positively associated with preclinical prostate cancer
risk; as caloric intake increased, cancer risk rose significantly.52 The greatest risk was for men
who consumed more than 3475 calories/day.

The mechanism involved may be related to the decrease in IGF-I observed when caloric intake is
restricted.5292

A cohort study reported obese men to have a 20% increased risk of dying from prostate cancer
and those men who were severely obese had a 34% elevated risk.93

This research was further supported by recent evidence that obesity is a risk factor for aggressive
prostate cancer.
94-95

Recently, researchers conducted an 11-day study where men followed the Pritikin program.35
The Pritikin program focuses on a diet that is high in vegetables, fruits, whole grains, and very low
in fat in combination with 60 minutes of daily exercise.

Serum IGF-I decreased by 20% after following the program for 11 days. This reduction in IGF-I
may be related to the lower serum insulin levels observed via a healthy low fat plant-based diet
and regular exercise.

These findings were further substantiated by researchers who placed blood serums of three groups
of men (Pritikin followers of 14 years, regular exercisers of 14 years with no modified diet, and
sedentary overweight men who consumed a high-fat, high-sugar diet) in culture dishes containing
prostate cancer cells.81

In a mere three days, researchers reported significant change in the cells. The blood serum of
the Pritikin followers destroyed 50% of the prostate cancer cells compared to the exercise-only
group where approximately 25% of the cells were destroyed and less than 3% of the cancer
cells were destroyed in the overweight, sedentary men eating a more typical high-fat
American diet.

Men who consumed tomato sauce 2-4 times weekly had a 34% lower risk for prostate cancer in
the largest prospective study to date.25

Thirty-two men with prostate cancer consumed 30 mg daily lycopene in the form of tomato
sauce for 3 weeks; researchers reported a 28% reduction in oxidative DNA damage and a 17.5%
decrease in PSA values.
101-102

In a smaller study where men consumed 30 mg lycopene daily for three weeks, men had 18%
lower PSA levels whereas the control group had a 14% increase in PSA levels.
99

Dietary sources include tomato products, such as tomato juice, V-8 juice, spaghetti sauce, and
ketchup as well as guava, grapefruit, papaya, and watermelon.

Cooked tomato products or juices contain higher amounts of lycopene.

Additionally, lycopene-rich foods are best absorbed in the presence of fat (such as a small amount
of olive oil).103

As with most nutrients and non-nutrients, it is best to obtain lycopene from foods. Supplements
appear to be capable of interfering with normal nutrition by promoting oxidative damage, which
increases cancer risk.104

How much do I need? Research indicates positive changes with 30 mg lycopene daily, which would
be approximately:

Antioxidant, which scavenges free radicals and suppresses damage due to oxidation in the tissues.

Selenium appears to inhibit cellular changes that may lead to prostate cancer. Selenium may also
work to inhibit angiogenesis105 and induce apoptosis or cell death.106

Angiogenesis may be defined as the growth of new blood vessels. In cancer, new vessels allow
tumor cells to escape into the circulation and lodge in other organs (tumor metastases) as well
as enable a tumor to grow.

Selenium has consistently been reported to reduce risk of prostate cancer.107-110
Low plasma selenium is associated with a 4 to 5-fold increased risk of prostate cancer.111

Additionally, selenium supplements have been shown to decrease the recurrence of prostate cancer
by 63%.107

Some research indicates that the combination of selenium and vitamin E may work synergistically
in reducing risk for prostate cancer.112 This combination is currently being reviewed in the
Selenium and Vitamin E Chemoprevention Trial (SELECT).113
Dietary sources include Brazil nuts, seafood, enriched brewer's yeast, and grains. Selenium content
depends somewhat on the amount in the soil in which the products are grown.

Some evidence suggests higher dosages (more than 1000 mg daily) may actually promote oxidative
damage. There are, however, other studies that have not observed adverse effects with vitamin C
supplementation.

Cancer incidence reduced by 33% and death from prostate cancer reduced 41% in a 6-year follow-
up study where men consumed 50-100 IU vitamin E.121

Vitamin E may reduce the incidence of prostate cancer, and also lower the rate of conversion from
latent to aggressive forms of prostate cancer.

Results suggest that long-term vitamin E (alpha-tocopherol) supplementation decreases serum
androgen concentrations, which is related to a reduced incidence of and mortality from prostate
cancer.110

Researchers reported lower serum gamma-tocopherol (a form of vitamin E) values in men with
prostate cancer in a recent cohort study.125 Furthermore, large doses of alpha-tocopherol suppress
levels of gamma-tocopherol.
127-129

The most provocative study found that men with the highest plasma gamma-tocopherol concentrations
had a significantly fivefold lower risk of prostate cancer compared with men in the lowest
quintile. 124 This effect was not significant for plasma alpha-tocopherol concentrations.

Other researchers have also found gamma-tocopherol to offer a protective effect against prostate
cancer.125-127

Dietary sources of vitamin E include vegetable oils, wheat germ, nuts, seeds, soybeans, sweet
potatoes, and avocado. Due to the high fat content of many dietary sources, a supplement may be
beneficial.

Many studies used a 400 IU vitamin E supplement daily, however, a multi-vitamin may easily
provide 50-100 IU vitamin E.

There has been considerable discussion regarding the different forms of vitamin E.

Natural forms of vitamin E (gamma-tocopherol, d-alpha-tocopherol) appear to be better
absorbed by the body, but are more expensive.131-132 A supplement containing mixed
tocopherols (d-alpha, gamma, beta) and tocotrienols is preferred. The combination of gammaand
alpha-tocopherol may offer greater protection from DNA damage than alpha-tocopherol
alone.133
Many of the studies on vitamin E and prostate cancer have used synthetic forms of vitamin E
(dl-alpha-tocopherol).
110121131134
A recent study, however, reported that the natural
form of vitamin E was more effective in the suppression of prostate cancer, and at a lower
concentration.131

Many studies indicate that in populations that consume high amounts of garlic, scallions, onions,
leeks, and shallots (all members of the same plant family) there is a reduced rate of overall cancer.
1427140-141

These allium vegetables are rich in flavonoids and organosulfur compounds that have anti-cancer
properties.

A Japanese study found that men who consumed 1/3 oz. or more of one of the allium-rich foods
mentioned above had approximately 50% reduction in prostate cancer risk compared with men
who consumed lesser amounts.140

Natural components in meat, such as amino acids, creatine, and polysaccharide precursors, are
converted to HCA's during high-temperature cooking. HCA's are known to cause cancer in laboratory
animals.
143-146
While human research is forthcoming,
143147-150
one study has observed no association between HCA's and prostate cancer.151

It may be that cancer risk is heightened in people who metabolize these compounds more rapidly.
Some individuals appear to have genes that encode enzyme production, which readily metabolize
HCA's.147152

The most important variables contributing to the formation of HCA's are:
143153

A cup of green tea daily would likely be a healthy addition to your diet, but evidence suggests that
3 or more cups are needed for the cancer protective effects.158

Green tea does naturally contain caffeine although a much lower amount than coffee or black tea.
Although decaffeinated green tea is also available, reports suggest that the phytochemical content
may be two-thirds less than regular green tea.

Vitamin D is known to inhibit prostate cancer in animals 180-184 and although human research
remains unclear, vitamin D appears to be of benefit.
108185-187

Vitamin D is believed to be
important in the protection of human prostate cells.
187-190

Epidemiological studies indicate that sunlight exposure is inversely proportional to prostate cancer
mortality and that prostate cancer risk is greater in men with lower levels of vitamin D.
185-186188191-192

A case-control study observed elevated cancer risk in men with both low (less than 19 nmol/l) and
high (more than 80 nmol/l) serum 25(OH)-vitamin D levels.
186 Men with the lowest risk had
normal serum 25(OH)-vitamin D levels ranging between 40-60 nmol/l.

A recent study on advanced prostate cancer reported that the combination of vitamin D and the chemotherapy
agent taxotere was twice as effective as taxotere alone based on PSA responses.193

Excessive doses of vitamin D (more than 2000 IU daily), however, can be toxic and cause high
levels of calcium in the blood.

One theory is that high amounts of calcium (more than 2000 mg daily) suppress circulating
vitamin D blood levels.108194

The relationship between dairy foods and increased prostate cancer risk may be due to the high
calcium content in dairy and/or to the animal fats in dairy.
45194

Some studies using skim or low-fat milk have found an increased association with prostate
cancer, supporting the calcium connection.45194

Men who drank more than 6 glasses of milk a week had lower levels of vitamin D than men who
drank fewer than 2 glasses of milk a week.

One analysis identified a four- to fivefold risk elevation with very high (more than 2000 mg daily) or
very low calcium intakes (less than 500 mg daily).
108
A recent study found that higher calcium intakes resulted in a modest 7% increase risk of localized
prostate cancer, but more than 200% increased risk for advanced prostate cancer compared to
men with the lowest calcium intake.
90

Additionally, a positive association between IGF-I and intake of milk, dairy products, and calcium
has been reported.195

Thus, it is recommended to consume adequate amounts of vitamin D and calcium, but to avoid
high calcium intakes (more than 2000 mg daily).

When eating in restaurants, avoid foods that may have bacterial contamination, including sushi,
salad bars, buffets, unpasteurized beverages or food products, and raw or undercooked meat,
poultry, fish, and eggs.

This botanical, composed of flavonoids, water-soluble polysaccharides, and free fatty acids, is
believed to function as an anti-androgen and anti-inflammatory agent.209

Saw palmetto may reduce the growth of normal or malignant prostate cells by slowing the conversion
of testosterone to DHT.210

Research also indicates beneficial effects on urinary flow rates in men with enlarged prostates, or
benign prostatic hyperplasia (BPH).209

320 mg daily seems to be effective.

There is currently no conclusive scientific evidence regarding saw palmetto and prostate cancer.

It has been theorized by some physicians that saw palmetto may, like the drug Proscar, lower PSA
values. It is not clear, however, if there is any effect on the tumor. In other words, saw palmetto
may mask the cancer.

The use of saw palmetto may exclude an individual from participating in certain clinical trials.

Reprinted by permission -
For additional information or resources, please visit the Ida and Joseph Friend Cancer
Resource Center at 1600 Divisadero Street on the first floor, or call (415) 885-3693. The information
in this publication is designed for educational purposes only and is not intended to
replace the advice of your physician or health care provider, as each patient's circumstances
are individual. We encourage you to discuss with your physician any questions and concerns
that you may have.